oh dear brett, i am afraid i misread, my apologies…!:scared: i got excited about something different for a sec! interesting though… however, i still like the idea of an “unlimited” class… of course, such a class might not last longer than the first generation of boats, as it is quite possible that we would find that making footys that “high-tech” simply doesn’t work…:rolleyes:
I know you were just musing, but I would like to see some electronic restrictions lifted. The whole li-po/regulator = long run time/light-weight thing is always on me mind.
As for my history, that is cleared constantly, so i gotta hunt it down.
I know it was a french site, and was a IOM or M class site.
I recall starting on Anderswallin, then to a few comercial sites, into foreign forums, found some links, and one of their topics was this guy building the wee IOMs.
Will look tonight.
thinking along the lines of using light weight stuf anyone looked into these i know that the fact there scaled down meas there guna be mutch good but there the right length and would be interesting to see if you tock a mold of one how it would perform the second looks to have a litl more volume
http://cgi.ebay.co.uk/STUNNING-RACING-YACHT-ONEWORLD-USA-67-MODEL_W0QQitemZ260197214700
the bulb on the “One World” model is massive! lol… the VOR boat is pretty though
unfortunately, as nigel has found, (grins) the scale hullshapes don’t seem to lend themselves to great footy useage… at least, as the rules are currently, they seem to lack the disp. to hold all the necessary items for sailing… they might, however, make pretty cool freesailers!
Do I detect a great shift in Footy design technique? Are we moving towards a design technique in which the starting point is not the graphics, but a rough weight estimate.
Please accept that I am not being in any way sarcastic (well, hardly any way - how could I be so false to type?) when I say that I am very impressed and (if I have any right to be) proud of you all. Few people on the Footy class had had any previous experience of yacht design, full size or model, when they embarked on their first Footy design.
What has been achieved by the Barretts and the Nigels and … is tremendous and driven by a lot of imagination. Might a suggest for 2008 a little more technical understanding of basic naval architecture and a slightly better appreciation of the Yacht Designer’s Casserole Book?
For formal naval atchitcture, the bst work of probavly Elements of Yacht Design by Norman Skene. A reprint of the first editon is available from Amazon. Water hasn’t changed much over the last 80-odd years.
The Casserole Book is harder. The best is
Elements de vitesse des coques by Jean-Marie Finot
Publisher : Arthaud (8 January 1992)
ISBN-10: 2700301781
ISBN-13: 978-2700301786
It is a delightfully simple book that provides a very profound analysis of what features of hulls produce what effects and how they interact. It’s two probems are that it is in French and is out of print. It may be possible to have it translated through Footy class contacts.
Finally, we need a Big Dumb-Dumb’s Guide to Engineering Tiny Stresses. Any of the M.Eng’s out there want to write one? We’ll see if we can get it published. My vision is essentially of an essay thay explains why a moment of inertia is not a tea-break and how a sandwich works. Only the very simplest numerical methods are required. I doubt if the author is going to get rich, but I don’t think the publisher will either!
So - full agead into the new year!
“Are we moving towards a design technique in which the starting point is not the graphics, but a rough weight estimate”.
The Lajabless was designed that way, as compared to the “Open Footy”.
Deck style on it is constantly changing, but the weight-estimated hull remains.
“For formal naval atchitcture, the bst work of probavly Elements of Yacht Design by Norman Skene. A reprint of the first editon is available from Amazon. Water hasn’t changed much over the last 80-odd years”.
Great book. The library is always out.
“a moment of inertia is not a tea-break and how a sandwich works”.
Awesome :lol:
I had a head start, because Angus phoned me to suggest that the Curved Air Press might bring out an Englished version, but a search of ABEbooks, my first line of enquiryfor anything on paper, produced no available copies. I found one eventually via amazon.fr. A secondhand copy from one of their associates. It was the last one, so others may actually have to wait until we can get it translated and published. As it’s relatively recent, we shall also have to negotiate a permission eith the author and publisher.
Russell
While i whole-heartedly support moving footy design toward a more numeric, empirical approach, i must (part in jest, part in all deadly seriousness) point out the fly in the ointment… namely that the man who is considered the “wizard” and the “father of modern yacht design” (at least state-side… i dunno if the brits accept him yet… :devil3: :sly: ) designed many of his decidedly successful yachts by carving them to what he felt looked right, fairing them by eye and by touch, and that was that… :graduate:
Graham; good point, I only use rechargeable cells and overlooked the existence of AAA lithium’s. I am still surprised at the fuss but now it’s tinged with embarrassment as well .
One more point, improving the performance of all Footys will make it- the class- more attractive in comparison to all the other small sports boats, as the class is competing for sailors against the likes of Micro Magics - 612s etc.
Every little helps.
Brett’s comment on speed differences is worth remembering. I believe in the 12m America’s cup days, a one hundredth of one percent increase in speed was considered to be a design break through?. Try measuring that in Footy terms. Many races have been won with slow boats but fast, well prepared sailors.
It would be interesting to try a string of really light boats - cheaper and easier with free sailors. My lightest was around 140 gms and 60% ballast ratio. I sailed that in the river -happy roller coaster ride over big waves. A short chop on a small pond might be a problem. I feel a foolish design coming on.
The method of design -CAD or carving- is unimportant, it’s just a different way of recording the shape you see in your mind. Understanding what the shape should be, that’s the bit that matters.
Making the sums add up helps as well. So does being a Genius.
History man. I look forward to seeing an English edition. I am assuming Angus has already talked you into doing the translation:p
Actually, the edition you want is the second, which has additional material including a discussion of model yachting. Skene was a model yachtsman (we have plans for a lovely 22-incher he designed) and was the Measurer for the Marblehead Model Yacht Club.
Cheers,
Earl
Barrett, if I assume you are talking about the Wizard of Bristol, aka Nathanial J. Herreshoff, you are talking romantic tosh. Forget about l’il ole Cap’n Nat sitting down by the beech an a barrel, looking into the distance with a saolor’s china-blue eye and putting all for his soul into a block of wood …
Reality was that Nathanial Herreshoff (forget about the ‘Captain’: he got it from a brief period as a steamship captain on the Hudson, I think). Came out ver close to top of his class in Mechanival Engineering at MIT. In many ways he was the most analytical naval architect who had ever lived. The story about the models whittled from blocks of wood isn’t untrue, but the context is rather different. Before a design got anywhere near a block of wood, it had been calculated and its line plan drawn (mostly in that order). The half-model was big - mich bigger than had been the case before Herreshoff’s time - and was used to do final fairing to a very high degree of accuracy. The offsets were taken off - again, to great accuracy - by dial gauges running in x-y coordinate frames.
This technique (with slight variation) became the norm for building ships but never really caught on in yachts. Presumably the extra expense in lofting was worthwhile.
So please don’t dininish one of the great naval architects of all time by looking him look like some sort of whittler. He may of course also have used a piece of wood from time to time to try and work how to blend two apparantly incompatible shapes. I use plasticene.
Er, not exactly. L. Francis, Nathael’s son, summarized his methods this way:
“But with good reason he chose to develop his shapes with models only. There are no lines drawings of the yachts and boats he designed.”
The process as described by L. Francis was as follows:
“First, he made a small sketch of the yacht for which he was to fashion the model. The sketch was often quite small and almost always made on a pad of paper ten and one half inches by eight inches. This sketch sometimes included some construction if points of construction were to affect the model, and the dimensions worked out on this sketch were the length overall, length on water line, draft, beam, and freeboard at three points. The principal thing on the sketch would be a carefully drawn midship section at the same scale as the model was to be.”
Then he would cut the profile, sheer, and deck line and use a template to transfer the midship section. After that he carved with a set of modified Stanley 101 thumb planes and faired with battens, sanded, shellacked, and the offsets were taken off. L. Francis, who worked with his father as well as Starling Burgess (and Norman Skene, and Frank Paine) said that his father could do a model in one-half to one-quarter the time that Burgess took to do a lines plan.
Source: Herreshoff, L. Francis, “Capt. Nat Herreshoff” Sheridan House, 1953 pg 129 ff.
I’ve attached a scan of a typical sketch. Anyone still skeptical that Herreshoff worked almost exclusively in three dimensions should take a virtual tour of the model room in the Herreshoff Museum:
http://00002vw.previewcoxhosting.com/images/Virtual/HerreshoffQTVR2small.mov
which has over 500 half hulls. So he was definitely some sort of whittler, in the sense that Michelangelo was some sort of ceiling painter 
As an aside, I spent quite a few hours in the model room documenting and reverse engineering the vane gears Herreshoff devised for the sailing models he amused himself with in his last years in Florida. If you’d like a PDF copy if the USVMYG newsletter article describing them emailed to you, feel free to PM me.
Cheers,
Earl
Thanks Earl for the link to the model room.
I guess he was just using an early version of “freeship” in essence
I am sure though he must have made some basic displacement calculations(you can do this easily based on the midship section that you discribe)
If my account is wrong or misleading, I apologise most most humbly. I had it in personal conversation with Capt. J.H. Illingworth RN (Ret), well known as a yachtsman (Maid of Malham, Myth of Malham) and as one of the foremost British racing yacht designers of the 1950s and 60s (Belmore, Maica, Outlaw, Oryx, Dambuster, Fabius, Blue Charm. Top Hat, Toby Jug, Contrail, Blue Dista …).
Apart from pure mistake on Capt. Illingworth’s part, the only explanation I can give was that this was practice of some other part of the Herreshoff Manufacturing Company. The context of the conversation was Capt. Illingworth telling me (then aged about 15) some important truths about how to be a yacht designer. I shall see if my father, who know Illingworth well and arranged to talk, has any recollections. What is cetainly common to both versions is that Herreshoff could produce drawings for the shop floor faster and hence cheaper than any of his rivals.
Oh, heavens, no apologies solicited or needed. My guess is that Illingworth was referring to L. Francis (“Skipper”), who would have been a contemporary (b. 1890 d. 1972) and who was of course no mean designer of oceangoing craft. L. Francis was definitely of the lines plans school.
BTW, I enjoyed all of Illingworth’s books, but my favorite is “Where Seconds Count,” which is fascinating for anybody interested in match racing.
Cheers,
Earl
you guessed aright Angus my friend. i was speaking in reference to “Nat”
G. Herreshoff. if i spoke amiss i must most sincerely and totally apologize, and it most certainly was not my intent to belittle, or at all detract from his work! the biographies i have read, along with bits and pieces of other things i have picked up from what i thought were reliable sources, led me to make the statement i did. as i said, if i spoke hastily, and thus incorrectly, i apologize.
alright gentlemen! that item of business taken care of, lets return to the regular programing! (grins)
A propos Herreshoff’s design methods, my understanding is that he was essentially a whittler, not because he didn’t know any better, but because he preferred it that way. More recently Chevalier, who did the drawings for the big America’s Cup book of designs that he wrote with Taglang, made half models of many of the yachts to get a three dimensional grip on what they were really like, particularly where there were conflicting versions of what the lines actually were. Over 20 drawings purporting to be ‘America’ .
There is the famous, but possibly apochryphal, remark attributed to G L Watson, designer of several America’s Cup challengers. One of them (I forget which) had been designed with the aid of the Denny test tank, then regarded as the latest high tech design tool. The Admirallty had had one at Torquay and later at Haslar run by the Froudes, father and son, but Denny’s were the first to have a tank available for commercial work.
Watson’s design ideas were modelled and tank tested, but his boat went down to the defender without much of a struggle. He is alleged to have said ‘If only Cap’ n Nat had a test tank!’.
Russell
While we’re on the subject of carving hulls, let me pass on the advice I was given by an old patternmaker many years ago:
A traditional fair hull is defined by three sections: fore, mid, and after master sections. All other sections are derived from these three by the fairing process. Once you have the hull cut to profile and plan, start with carving down to the mid master template. Then do the afterbody, fairing to the mod. Do the forebody last, fairing to mid and aft. This reflects the design wisdom that the afterbody, or “run” is the most important part of the hull. Also, as L. Francis said about his father’s methods, using battens on a carved hull is like fairing on paper with hundreds of diagonals.
When asked for advice, especially by beginners, on doing a carved-hull (bread and butter) sailing yacht, I always recommend they do a half hull first, so they can see what the hull really looks like and encounter any tricky spots before cutting into the real thing.
Cheers,
Earl